Conventional guy cables have proven to be a structurally sound and economical solution to the need for balancing asymmetrical forces on overhead service poles used by utilities. Unfortunately, there are often situations along roadways where it is difficult, if not impossible, to avoid placing guys in designated clear zones adjacent to the roadway proper. Unless the guy is capable of breaking in response to vehicle impact, it is then required that the utility poles be set back in order that the guys can be properly positioned outside the clear zone. Placement of the guy anchor outside the clear zone can substantially increase the cost of acquiring the necessary rights of way.
A typical cable guy will not yield when struck by a vehicle moving at moderate speeds. The pole itself will normally fail before the guy. Because one end of a cable guy is firmly fixed to a ground anchor and its other end is attached to the upper section of a supported pole, the pole will be either pulled directly toward the vehicle or the tensioned cable guy will slice through the vehicle. This creates a serious potential for injury to the vehicle's occupants.
To assist in preventing the damage and injury caused by standard down guys, efforts have been made to develop a down guy attachment that can be effectively used in designated clear zones. Earlier efforts preceding the development of this invention used a length of galvanized pipe as a transition between the standard guy cable anchor and a guy cable. It was anticipated that the root of the thread at the junction on an upper clevis on the pipe would provide an adequate stress riser to initiate fracture of the pipe. While successful initial tests of the frangible link were reported publicly in 1985 and 1989, I later found that these results could not be consistently duplicated. The present invention is an offshoot of such research efforts. It has proven to yield consistent results satisfactory to industry needs.